Fresnel liquid crystal lens and 2D/3D switchable display panel

Abstract

A Fresnel liquid crystal lens and a 2D/3D switchable display panel are provided. The Fresnel liquid crystal lens includes a plurality of liquid crystal lens units. Each liquid crystal lens unit includes a first main electrode and two first sub electrodes disposed on a first substrate, a second main electrode and two second sub electrodes disposed on a second substrate, and a liquid crystal layer disposed between the first and second substrates. The first sub electrodes are disposed on two opposite sides of the first main electrode, and a first gap is formed between the first main electrode and the first sub electrode. The second sub electrodes are disposed on two opposite sides of the second main electrode, and a second gap is formed between the second main electrode and the second sub electrode. In a vertical projection direction, the first main electrode overlaps the second main electrode, the first sub electrodes overlap the second sub electrodes, and the first main electrode partially overlaps the second sub electrodes.

What is claimed is: 
     
       1. A Fresnel liquid crystal lens, comprising:
 a first substrate; 
 a second substrate, disposed opposite to the first substrate; 
 a liquid crystal layer, disposed between the first substrate and the second substrate; 
 a plurality of first liquid crystal lens units, wherein each of the first liquid crystal lens units comprises:
 a first main electrode, disposed on a surface of the first substrate facing the liquid crystal layer, wherein the first main electrode has a first voltage; 
 at least two first sub electrodes, disposed on the surface of the first substrate facing the liquid crystal layer and located on two opposite sides of the first main electrode, wherein the first sub electrodes have a second voltage, and a first gap exists between the first main electrode and each of the first sub electrodes; 
 a second main electrode, disposed on a surface of the second substrate facing the liquid crystal layer, wherein the second main electrode has a third voltage; and 
 at least two second sub electrodes, disposed on the surface of the second substrate facing the liquid crystal layer and located on two opposite sides of the second main electrode, wherein the second sub electrodes have a fourth voltage, a second gap exists between the second main electrode and each of the second sub electrodes, the first main electrode overlaps the second main electrode in a vertical projection direction, the first sub electrodes overlap the second sub electrodes in the vertical projection direction respectively, and the first main electrode partially overlaps the second sub electrodes in the vertical projection direction respectively; and 
 
 a plurality of second liquid crystal lens units, the second liquid crystal lens units and the first liquid crystal lens units being arranged alternately, wherein each of the second liquid crystal lens units comprises:
 a third main electrode, disposed on the surface of the second substrate facing the liquid crystal layer, wherein the third main electrode has a fifth voltage; 
 at least two third sub electrodes, disposed on the surface of the second substrate facing the liquid crystal layer and located on two opposite sides of the third main electrode, wherein the third sub electrodes have a sixth voltage, and a third gap exists between the third main electrode and each of the third sub electrodes; 
 a fourth main electrode, disposed on the surface of the first substrate facing the liquid crystal layer, wherein the fourth main electrode has a seventh voltage; and 
 at least two fourth sub electrodes, disposed on the surface of the first substrate facing the liquid crystal layer and located on two opposite sides of the fourth main electrode, wherein the fourth sub electrodes have an eighth voltage, a fourth gap exists between the fourth main electrode and each of the fourth sub electrodes, the third main electrode overlaps the fourth main electrode in the vertical projection direction, the third sub electrodes overlap the fourth sub electrodes in the vertical projection direction respectively, and the third main electrode partially overlaps the fourth sub electrodes in the vertical projection direction respectively. 
 
 
     
     
       2. The Fresnel liquid crystal lens of  claim 1 , wherein a dimension of the first main electrode is substantially equal to a dimension of the third main electrode, a dimension of the second main electrode is substantially equal to a dimension of the fourth main electrode, and the dimension of the first main electrode is larger than the dimension of the second main electrode. 
     
     
       3. The Fresnel liquid crystal lens of  claim 1 , wherein a dimension of each of the first sub electrodes is substantially equal to a dimension of each of the third sub electrodes, a dimension of each of the second sub electrodes is substantially equal to a dimension of each of the fourth sub electrodes, and the dimension of each of the first sub electrodes is smaller than the dimension of each of the second sub electrodes. 
     
     
       4. The Fresnel liquid crystal lens of  claim 1 , wherein the first gap is substantially equal to the third gap, the second gap is substantially equal to the fourth gap, and the first gap is smaller than the second gap. 
     
     
       5. The Fresnel liquid crystal lens of  claim 1 , wherein the first main electrode and the second sub electrode have a first overlapping portion in the vertical projection direction, the first overlapping portion has a first overlapping width substantially greater than 0 micrometer and less than or equal to 50 micrometers, the third main electrode and the fourth sub electrode have a second overlapping portion in the vertical projection direction, and the second overlapping portion has a second overlapping width substantially greater than 0 micrometer and less than or equal to 50 micrometers. 
     
     
       6. The Fresnel liquid crystal lens of  claim 1 , wherein the second sub electrode and the fourth sub electrode have a third overlapping portion, and the third overlapping portion has a third overlapping width substantially greater than 0 micrometer and less than or equal to 50 micrometers. 
     
     
       7. The Fresnel liquid crystal lens of  claim 1 , wherein a polarity of the second voltage, the fourth voltage, the fifth voltage and the seventh voltage is opposite to a polarity of the first voltage, the third voltage, the sixth voltage and the eighth voltage. 
     
     
       8. The Fresnel liquid crystal lens of  claim 1 , wherein the first main electrode and the second main electrode have a first voltage difference, the first main electrode and the second sub electrode have a second voltage difference, an absolute value of the first voltage difference is less than an absolute value of the second voltage difference, a voltage difference between the first sub electrode and the second sub electrode is substantially equal to 0, the third main electrode and the fourth main electrode have a third voltage difference, the third main electrode and the fourth sub electrode have a fourth voltage difference, an absolute value of the third voltage difference is less than an absolute value of the fourth voltage difference, and a voltage difference between the third sub electrode and the fourth sub electrode is substantially equal to 0. 
     
     
       9. The Fresnel liquid crystal lens of  claim 1 , wherein
 each of the first liquid crystal lens units further comprises:
 at least one fifth sub electrode, disposed on the surface of the first substrate facing the liquid crystal layer and located on at least one of two opposite sides of the first sub electrodes with respect to the first main electrode, wherein the at least one fifth sub electrode has a ninth voltage; and 
 at least one sixth sub electrode, disposed on the surface of the second substrate facing the liquid crystal layer and located on at least one of two opposite sides of the second sub electrodes with respect to the second main electrode, wherein the at least one sixth sub electrode has a tenth voltage; and 
 
 each of the second liquid crystal lens units further comprises:
 at least one seventh sub electrodes, disposed on the surface of the second substrate facing the liquid crystal layer and located on at least one of two opposite sides of the third sub electrodes with respect to the third main electrode, wherein the at least one seventh sub electrode has an eleventh voltage; and 
 at least one eighth sub electrodes, disposed on the surface of the first substrate facing the liquid crystal layer and located on at least one of two opposite sides of the fourth sub electrodes with respect to the fourth main electrode, wherein the at least one eighth sub electrode has a twelfth voltage. 
 
 
     
     
       10. The Fresnel liquid crystal lens of  claim 9 , wherein a dimension of the at least one fifth sub electrode is substantially equal to a dimension of the at least one seventh sub electrode, a dimension of the at least one sixth sub electrode is substantially equal to a dimension of the at least one eighth sub electrode, and the dimension of the at least one sixth sub electrode is smaller than the dimension of the at least one fifth sub electrode. 
     
     
       11. The Fresnel liquid crystal lens of  claim 9 , wherein the fifth sub electrode overlaps the sixth sub electrode in the vertical projection direction, the seventh sub electrode overlaps the eighth sub electrode in the vertical projection direction, the fifth sub electrode partially overlaps the second sub electrode and the seventh sub electrode in the vertical projection direction respectively, and the seventh sub electrode partially overlaps the fourth sub electrode and the fifth sub electrode in the vertical projection direction respectively. 
     
     
       12. The Fresnel liquid crystal lens of  claim 9 , wherein the ninth voltage is substantially equal to the first voltage, the tenth voltage is substantially equal to the first voltage, the eleventh voltage is substantially equal to the fifth voltage, and the twelfth voltage is substantially equal to the fifth voltage. 
     
     
       13. The Fresnel liquid crystal lens of  claim 9 , wherein the fifth sub electrode and the second sub electrode have a fifth voltage difference, the seventh sub electrode and the fifth sub electrode have a sixth voltage difference, the seventh sub electrode and the fourth sub electrode have a seventh voltage difference, an absolute value of the fifth voltage difference is substantially equal to an absolute value of the sixth voltage difference, an absolute value of the fifth voltage difference is substantially equal to an absolute value of the seventh voltage difference, a voltage difference between the fifth sub electrode and the sixth sub electrode is substantially equal to 0, and a voltage difference between the seventh sub electrode and the eighth sub electrode is substantially equal to 0. 
     
     
       14. The Fresnel liquid crystal lens of  claim 1 , wherein the first liquid crystal lens units and the second liquid crystal lens units are alternately arranged along a linear direction. 
     
     
       15. A 2D/3D switchable display panel, comprising:
 the Fresnel liquid crystal lens of  claim 1 ; and 
 a display panel, overlapping the Fresnel liquid crystal lens, wherein the display panel comprises:
 a third substrate; 
 a fourth substrate, disposed opposite to the third substrate; and 
 a display medium layer, disposed between the third substrate and the fourth substrate. 
 
 
     
     
       16. The 2D/3D switchable display panel of  claim 15 , further comprising a touch input device, overlapping the Fresnel liquid crystal lens and the display panel.